Vu-Mod Hooks fails

My VU-MOD vehicle plugin is working for a certain amount of time, than it a hook stops working and problems appear. I get these errors randomly after a while:

[lua]
ERROR: Hook ‘vmExitCar’ Failed: [gamemodes\cider\gamemode\core\plugins\vehicles\sv_init.lua:165] attempt to index field ‘VehicleTable’ (a nil value)
Removing Hook ‘vmExitCar’
[/lua]
[lua]
ERROR: Hook ‘SpawnedVehicle’ Failed: [gamemodes\cider\gamemode\core\plugins\vehicles\sv_init.lua:209] attempt to index local ‘seatdata’ (a nil value)
Removing Hook ‘SpawnedVehicle’
[/lua]
[lua]
ERROR: Hook ‘vmEnterVehicle’ Failed: [gamemodes\cider\gamemode\core\plugins\vehicles\sv_init.lua:64] attempt to index field ‘Ent’ (a nil value)
Removing Hook ‘vmEnterVehicle’
[/lua]
My question is: How can I know what’s causing this, so I can fix it? Or are there already people that are known with VU-MOD that fixed this?